What does the "Absolute Height" Display Function Mean under "Set Benchmark Height?"

Purpose of Absolute Height display function

This display option only applies if you are working with heights, and you need to adjust how height values appear after stationing.

There are two major use cases for this, both related to adjusting height to or from sea level values:

1. Control Point heights are measured at sea level, but CAD elements and layout points are at different elevations. You would like to adjust the visual control point height to be more relative to the CAD file you are working in.
2. CAD elements and layout points are at sea level (such as a civil drawing), but the control point heights are not. You would like to adjust the control point heights during your workflow to match the CAD heights.

Note: this is for visual purposes only. The exported point data will save the point heights based on the actual station height established during stationing. For more information on stationing with heights, see this article.

How-To: Open the Application

Open the application by navigating to "set station height" and select the "absolute height" option:

How-To: Set Correct Parameters

In the above example, my station was set with a 1.5m Station Height. I have indicated a 400m elevation adjustment to have it display as 401.5m, which I know to be the correct offset to reach sea level based on the control points or benchmark height I originally measured.

Now - visually, my software will guide me to my layout points as if I am at this new elevation. Layout and Control Point values will all adjust, visually, to show this new height value in the point list and on the CAD file.

How-To: Adjusting Height of Imported Data

These parameters are only necessary to adjust if adjusting the station's height itself is insufficient to get the height values that you would like.

Example: Adjust Control Control and CAD Height

In the above example, my imported control point file had heights that were not at sea level. However, I want the control points to visually be at sea level during my work. Therefore, as the example above indicates, I have adjusted my sea level offset to show 400m. The total station, which was stationed at "building zero," automatically adjusts its location based off of this new value to show its elevation according to the offset.

My layout points, also, were based on the same height system as the control, and I would like them to adjust as well. Now, when I layout, all of my height values will display based off of this offset.

Final Suggestion:

This function is for convenience only. If your workflow is able to manage heights without adjusting the height values on this screen, continue doing so.